1. Field of the Invention
This invention relates generally to a heat transferring member for a solder handling device for use in soldering, and more particularly to an electric soldering iron, and an electric desoldering tool with the heat transferring member.
2. Description of the State of the Art
Heretofore, in electric and electronic industries, a soldering method has been generally employed as a means for connecting and joining electronic components.
Various soldering methods are available, such as: a flow soldering method using a solder bath for immersing a printed-wiring board with electronic components into molten solder, or immersing a solder joining area directly into a jet flow of molten solder; a reflow soldering method of pre-applying solder paste in a given pattern onto a printed-wiring board by screen printing, placing surface-mount components on the printed-wiring board, and then passing the printed-wiring board through a high-temperature reflow furnace to melt the solder pattern to form a solder joint; and an iron soldering method including both a manual soldering operation using a tool such as an electric soldering iron, and a machine soldering method using a dedicated automatic machine with a soldering iron unit.
Soldering of electronic components onto wiring boards has been dominated by operations based on a flow soldering method or a reflow soldering method free of the need for human power or suitable for mass production. However, soldering for a particular component and repair operations often requires a manual tool, such as an electric soldering iron, to be handled by a skilled operator or a dedicated automated machine. In such a case, a soldering operation using the iron soldering method is essential.
As a conventional heat transferring member employed in soldering for the iron soldering method, there has been known one type which comprises a heat transfer body for melting solder, and an insert pipe made of stainless steel and inserted into a dead-ended hole formed in the heat transfer body, so that the heat from a heating member is conducted from the heat transfer body to solder via the insert pipe.
However, stainless steel has thermal conductivity less than copper. Therefore, considering heat transfer from the heating member to a surface of the heat transfer body, the insert pipe interposed therebetween causes deterioration in efficiency of the heat transfer from the heating member to the heat transfer body.
In this connection, U.S. Pat. No. 6,818,862 (entitled “Iron tip and electric soldering iron”) and International Patent Publication No. WO/2002/010477 A1 (entitled “Electric soldering iron tip and electric soldering iron”) disclose a technique for subjecting an inner surface of the hole of the heat transfer body directly to a surface modification treatment to prevent oxidation of the inner surface of the hole of the heat transfer body, instead of interposing the insert pipe between the heating member and the heat transfer body. However, the hole in the heat transfer body to receive therein the heating member is formed to define a dead-ended hole (also referred to as a non-through-hole or a blind hole) having a relatively large depth from a base end of the heat transfer body. Therefore, a flow of gas required for the surface modification treatment stagnates inside the hole to preclude a possibility to obtain a homogeneous surface-modified layer.
In view of the above conventional problems, there is a need for improved suppression of oxidation of a heat transfer body of a heat transferring member for a solder handling device, while maintaining high heat transfer efficiency.